The present invention is directed toward surfboards and similar boards used for water sports and more particularly, toward such boards that have an improved stringer that allows for improved and selective flexibility of the board.
Board-shaped riding vehicles have long been a part of water recreation, first as surfboards, and later as sail boards and body boards and the like. Originally, most surfboards were manufactured to be stiff and heavy, with hard exterior surfaces. In more recent years, however, surfboard and sail board manufacturers have utilized synthetic materials to make lightweight boards, and body boards are normally constructed from soft foam materials.
Most currently available surfboards generally have light density core material glued to a wood stringer positioned at a longitudinal centerline with the entire core and stringer then covered by a hard exterior skin layer. The purpose of the stringer is to provide structural strength to the surfboard. As can be appreciated, the flexibility of the stringer directly affects the flexibility of the surfboard.
Surfboards are required to flex some amount and at desired locations which may change depending on the surfing conditions and the skill level of the surfer. As pointed out above, almost all commercially available surfboards have one, or sometimes two, thin planar wood stringers that increase the strength of the board that is necessary because of the light density of the core material currently used.
The flex patterns and characteristics exhibited by existing surfboards are random, not pre-determined and less than optimal. This is mainly due to the random flex characteristics and resistance to flexing of the solid body stringer. Moreover, the material types and the width of the stringers also play a role in the random and uncontrolled flex characteristics. Because of limited flexibility, existing surfboards tend to break easily under harsh wave conditions or repetitive uses.
Therefore, it is desirable to provide a water sports board having an improved flexibility. It is further desirable to provide a water sports board with selected or predetermined desired flex patterns, which ultimately enhances maneuverability and performance of the board to the rider. Moreover, it is also desirable to provide water sports boards with improved shock dampening property to enhance durability of the boards particularly in extreme environments.
One suggestion for improving the flexibility characteristics of a surfboard is disclosed in U.S. Published Application No. 2009/0280704 to Fort. Fort proposed cutting holes or windows through the side of the stringer. While this may weaken the stringer allowing it to flex laterally, it does not increase the flexibility of the stringer or of the surfboard in any direction within the plane of the stringer, thereby limiting its effectiveness. Furthermore, when the surfboard core material is glued onto the stringer, the glue can enter the formed openings and solidify, which makes the stringer more rigid, thereby again reducing the flexibility of the stringer and the surfboard.
A need continues to exist, therefore, for an arrangement that allows a surfboard manufacturer to produce a surfboard with specifically desired flexibility characteristics.